Bendable Display Substrate Segmentation for Dead Space Reduction
Solution Overview
Problem
Conventional display devices face challenges in minimizing dead space and efficiently connecting substrate portions, which affects the overall display area and structural integrity, especially when bending is involved.
Innovation Solution
A display device design featuring a substrate with a bending area filled with organic material, supported by a flexible material, and connected through inorganic layers and wiring, allowing for a seamless integration of substrate portions and minimizing dead space by enabling flexible bending while maintaining electrical connectivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the substrate is made rigid to maintain structural integrity, then strength is improved, but flexibility deteriorates
Solution Approach 1:
The substrate is divided into a first substrate portion and a second substrate portion connected by a bending area. This segmentation allows different regions to have different mechanical properties: the first substrate portion maintains rigidity for structural integrity, while the bending area provides flexibility for bending operations.
Solution Approach 2:
The bending area is specifically designed with different properties than the rest of the substrate. It has reduced thickness and lacks certain layers (such as the encapsulation portion) in specific regions, creating local flexibility while maintaining overall structural integrity through the rigid first substrate portion.
2Strength
If the substrate thickness is increased to improve strength, then strength is improved, but bending capability deteriorates
Solution Approach 1:
The substrate thickness is segmented such that the first substrate portion has greater thickness for strength, while the bending area has reduced thickness to enable bending. This is achieved by having the bending area extend only partially through the thickness of the substrate and by selectively removing material in the bending area.
Solution Approach 2:
The substrate exhibits local quality variations where the bending area has different thickness and material composition compared to the first substrate portion. The bending area may have openings or reduced material density, allowing it to be flexible while the thicker first substrate portion maintains overall strength.
3Reliability
If wiring is made rigid to ensure electrical connectivity, then reliability is improved, but flexibility deteriorates
Solution Approach 1:
The wiring structure is segmented into rigid portions (such as pad terminals and intermediate wirings) and flexible portions (such as connection wirings in the bending area). This allows electrical connectivity to be maintained through the rigid segments while the flexible segments accommodate bending movements.
Solution Approach 2:
The wiring structure employs composite design with multiple layers and materials. The connection wiring in the bending area is designed to be flexible while maintaining electrical conductivity, potentially using materials or structures that combine electrical properties with mechanical flexibility to accommodate substrate bending.
4Reliability
If encapsulation is made extensive to protect the substrate, then reliability is improved, but dead space increases
Solution Approach 1:
The encapsulation portion is segmented to provide protection only where needed. It covers the first substrate portion and certain areas requiring protection, but is selectively absent or reduced in the bending area and other regions where encapsulation would create dead space or interfere with bending functionality.
Solution Approach 2:
The encapsulation portion exhibits local quality by being present in some areas and absent in others. It provides comprehensive protection over the display area and rigid substrate portions, while being selectively removed from the bending area to maintain flexibility and reduce dead space, creating a non-uniform encapsulation strategy.
Data Source
AI summary
A display device includes a substrate including a first substrate portion including a first area, a second substrate portion including a second area, and a bending area between the first substrate portion and the second substrate portion, the substrate being bendable around a bending axis that extends in a first direction, an encapsulation portion over the first substrate portion, an intermediate wiring including a first intermediate wiring portion in the first area and a second intermediate wiring portion in the second area, and a connection wiring including at least a portion in the bending area and connecting the first intermediate wiring portion to the second intermediate wiring portion.